硫代硫酸钠标准溶液结果偏差控制研究

目的]确认并探究影响硫代硫酸钠标定结果的偏差所在。方法]研究了影响硫代硫酸钠标准溶液稳定性的因素,剖析该溶液标定过程中的关键环节,并对相应关键点进行试验,控制其标定结果的相对偏差。结果]试验表明,参与硫代硫酸钠标定过程的水必须不含CO2和O2,是煮沸冷却水或新制备水,减少用水干扰;制备的溶液及静置过程中的溶液均需放置在避光条件下,避免环境对溶液造成影响;标定过程中静置完毕后应立即加水终止反应,确保结果的稳定,降低偏差;采用滴定一个样品加入一个碘化钾的方式进行试验,对控制偏差效果显著。结论]研究可为硫代硫酸钠标准溶液的制备提供参考。

Sodium Thiosulfate Standard Solution Results Deviation Control Research

Objective] To explore the deviation influencing standard solution of sodium thiosulfate.Method] The factors for influencing stability of sodium thiosulfate stable solution were studied,the key links in the solution calibration process were analyzed,the corresponding key points were tested for controlling the relative deviation of calibration results.Result] The results showed that,the involved water should be boiling cooling water or new preparation water without CO2 and O2;prepared solution and solution in statistic process should place away from sunshine,in order to avoid influence by environment;after statistics,water should be added for ending the reaction and guaranteeing stable of the results;adding a potassium iodide at a sample titration has significant effects on controlling the deviation.Conclusion] The study will provide reference for preparation of sodium thiosulfate standard solution.